big engine build, D-tronic quest for the engine guys Options

[02loftsmoor]

Every one said to keep you orginal engine stock,,So I bought a shortblock, I have a 2.0 crank lined up with rods, an 11lb flywheel and 2.0 heads. I was looking at useing 103mm cylinders. Is the D-tronic able to handle the larger bore???

my D-tronic if from my 1.7

Wes

[Mike Bellis]

Do you want it to run? or run well? I don't think the factory system can compensate for an extra 300cc's. Too many variables (more than extra CC's) for a "dumb" FI system to handle.

In my opinion, you would be better off going to programmable fuel injection.

[76-914]

if you have yellow injectors you'll need to change to green. you will need an A/F gauge installed to adjust (fatten) your MPS.

[r_towle]

Yes, it works with adjustment to the mps.

Rich

[JeffBowlsby]

I dont know how big that is but I thought there was general consensus that 2056 was the biggest reasonable size for stock Djet?

[02loftsmoor]

2366cc

I dont know how big that is but I thought there was general consensus that 2056 was the biggest reasonable size for stock Djet?

[02loftsmoor]

help me here,, MPS??

[messix]

manifold pressure sensor

[Mike Bellis]

2366cc

I dont know how big that is but I thought there was general consensus that 2056 was the biggest reasonable size for stock Djet?

I do not think you can run a 2.36L on the stock injection system. It is just too antiquated for such large displacement.

You might be able to modify a mechanical system from a Rabbit to work but that won't be easy either.

I think carbs or Megasquirt is in your future.

[messix]

go l-jet

many many aplications out there to build a system that will work

[02loftsmoor]

Never heard of I-Jet Mega squirt yes

go l-jet

many many aplications out there to build a system that will work

[messix]

Never heard of I-Jet Mega squirt yes

go l-jet

many many aplications out there to build a system that will work

l= small L

not i or I (IMG:style_emoticons/default/slap.gif)

[ConeDodger]

In my opinion it can be done but the compromises in driveability aren't worth the trouble.

[Mike Bellis]

In my opinion it can be done but the compromises in driveability aren't worth the trouble.

(IMG:style_emoticons/default/agree.gif)

Exactly! Which is why I first asked... "Do you want it to run? or run well?" Two different ways to drive.

There is nothing factory that you can just "bolt on" and go. Even if you can source enough L-Jet parts from various make and models, the money, frustration and time spent won't be worth it.

CB Performance has a programmable system for around $1700. Or McMark can build you a bolt on kit.

[02loftsmoor]

I may have to rethink this,, I have been reading up on the Mega squirt, is seems full of bugs, but what what I've been reading they may not fully understand the system,.

[Mike Bellis]

I may have to rethink this,, I have been reading up on the Mega squirt, is seems full of bugs, but what what I've been reading they may not fully understand the system,.

It's not full of bugs but you do need to understand tuning principals. Each engine, even if setup identically will need a slightly different tune. Most newer EFI systems have some sort of self tuning ability. But you need the basic tune to be close for it to work.

Find a tuner in your area and see what EFI system they specialize in. A Dyno and some tuning time is all you need for good running and HP.

[r_towle]

i will say it again.
it works with djet.

the injectors for the 2.0 liter support the 2.4 motor (71*103)
The mps needs to be tuned while driving, at idle, and under load.

But, the 'consensus' that is does not work is a disproven rumor.

rich

[VaccaRabite]

Rich, I don't doubt that it works.
I just doubt that it works well.

There is going to be a lot of heat soak with 103s.
Keeping the heads cool is going to be a challenge.

It might make a great AX engine, where heat is not as much of a concern as the run is only 1 minute or so and you only run 5 or 6 times a day. I was thinking about doing exactly that with the race car Scott and Mike and I were going to build - but that car would not have been street legal. Making the engine drive to the event and back w/o overheating would get expensive I bet.

Zach

[ConeDodger]

Rich, I don't doubt that it works.
I just doubt that it works well.

There is going to be a lot of heat soak with 103s.
Keeping the heads cool is going to be a challenge.

It might make a great AX engine, where heat is not as much of a concern as the run is only 1 minute or so and you only run 5 or 6 times a day. I was thinking about doing exactly that with the race car Scott and Mike and I were going to build - but that car would not have been street legal. Making the engine drive to the event and back w/o overheating would get expensive I bet.

Zach

(IMG:style_emoticons/default/agree.gif) My point is that the LJet is much more flexible and in my opinion less fragile than DJet. Before Chris Foley you couldn't pray for a decent MPS. You can easily get a AFM rebuilt...

[r_towle]

It works fine.
No heat issues, nothing dramatic nor complicated making it work just fine.

Is there more hp to seek out with carbs and a camshaft, sure there is.
Then you have heat issues.

For a very fun, and cheap fast motor, 71 * 103 will put a big smile on your face and with the same stroke, the injection functions just fine.

Have any of you guys with custom motors driven 10k miles yet?

It's really a simple build that has been done for over 30 years.
No complexity nor added stress from a longer stroke...which does add new stress.

Don't believe me, call and ask FAT performance.


Rich